The solution options are as follows:

• Establish alternatives to detect exceptions and automatically initiate a system failover, or redirect the request to a standby system. Implement code that leverages alternate nodes when a failed request is detected from an existing application.
• Design for instrumentation, such as events or performance counters, that detects performance problems or external system failures and exposes information through standard interfaces, such as, WMI, trace files, and event logs. Log performance, errors, exceptions and auditing information about calls made to other systems and services.
• Establish alternatives to manage unreliable application, failed APIs, and failed transactions. Identify queuing pending requests if the application goes offline.
• Design a store and forward or cached mechanism that allows requests to be stored when the target application is unavailable, and forward when the target is online.
• Design the solution leveraging queuing to provide a reliable alternative for asynchronous APIs.
• The solution should be capable of recovering from an error or exception based on your error and exception strategy
• The primary server serves all the requests, but a backup server is added to route traffic if the primary server goes down or is taken offline for upgrades.
• Data integrity is established with security controls/mechanisms which will prevent the third party from making any unauthorized access and/or changes to data.
• Database transactions ensure data integrity as it will be a full commit or a rollback based on success/failure status.
• The application should be able to go back to a previous version of a system in the event of failure. This depends on good source code management, good version control, and good rollout strategies.
• The application should be able to restore data in the case of loss or corruption. This is vital for many enterprises to go back to just before the incident occurred to avoid the painstaking task of recapturing the data between the last consistent backup and the time the incident occured.
• In the event of an application failure, you may fail-over to an alternative or standby site until the primary is back online. Establish the recoverability of an enterprise by defining the backup entities and contingency roadmap.